Continuous production of melamine-formaldehyde microcapsules using a mesostructured reactor

A mesostructured NETmix reactor was adapted to develop a continuous process to produce microcapsules, focusing on the steps commonly used in batch formulation: the emulsion and cure. Microcapsules were formed through a polycondensation process by coating Miglyol, a skin-hydrating emollient, with melamine-formaldehyde, which is a resistant shell material with surface smoothness. Different recirculation times were tested for the cure step. Microcapsules show a spherical shape and smooth membrane. Efficiencies of encapsulation of 75%, core contents of 70%, and diameters around 20 μm, ideal range for textile impregnation, were obtained. Scanning electron microscopy shows the integrity of microcapsules on textiles after impregnation and their flexible behavior. The thermogravimetric analysis confirmed the thermal stability of microcapsules up to 210 °C. With the NETmix reactor, it is possible to reduce the cure time of traditional batch formulation in 80%, producing microcapsules with similar characteristics in a continuous process.This work was supported by Associate Laboratory LSRE-LCM UID/EQU/50020/2019 funded by national funds through FCT/MCTES (PIDDAC) and Project TexBioPro, POCI-01- 0247-FEDER-003472, funded by FEDER, through COMPETE 2020, under PT2020.info:eu-repo/semantics/publishedVersio

Controlled variations in stimulus similarity during learning determine visual discrimination capacity in freely moving mice

The mouse is receiving growing interest as a model organism for studying visual perception. However, little is known about how discrimination and learning interact to produce visual conditioned responses. Here, we adapted a two-alternative forced-choice visual discrimination task for mice and examined how training with equiprobable stimuli of varying similarity influenced conditioned response and discrimination performance as a function of learning. Our results indicate that the slope of the gradients in similarity during training determined the learning rate, the maximum performance and the threshold for successful discrimination. Moreover, the learning process obeyed an inverse relationship between discrimination performance and discriminative resolution, implying that sensitivity within a similarity range cannot be improved without sacrificing performance in another. Our study demonstrates how the interplay between discrimination and learning controls visual discrimination capacity and introduces a new training protocol with quantitative measures to study perceptual learning and visually-guided behavior in freely moving mice

The effect of clinical experience, judgment task difficulty and time pressure on nurses’ confidence calibration in a high fidelity clinical simulation

Background: Misplaced or poorly calibrated confidence in healthcare professionals’ judgments compromises the quality of health care. Using higher fidelity clinical simulations to elicit clinicians’ confidence 'calibration' (i.e. overconfidence or underconfidence) in more realistic settings is a promising but underutilized tactic. In this study we examine nurses’ calibration of confidence with judgment accuracy for critical event risk assessment judgments in a high fidelity simulated clinical environment. The study also explores the effects of clinical experience, task difficulty and time pressure on the relationship between confidence and accuracy. Methods: 63 student and 34 experienced nurses made dichotomous risk assessments on 25 scenarios simulated in a high fidelity clinical environment. Each nurse also assigned a score (0–100) reflecting the level of confidence in their judgments. Scenarios were derived from real patient cases and classified as easy or difficult judgment tasks. Nurses made half of their judgments under time pressure. Confidence calibration statistics were calculated and calibration curves generated. Results: Nurse students were underconfident (mean over/underconfidence score −1.05) and experienced nurses overconfident (mean over/underconfidence score 6.56), P = 0.01. No significant differences in calibration and resolution were found between the two groups (P = 0.80 and P = 0.51, respectively). There was a significant interaction between time pressure and task difficulty on confidence (P = 0.008); time pressure increased confidence in easy cases but reduced confidence in difficult cases. Time pressure had no effect on confidence or accuracy. Judgment task difficulty impacted significantly on nurses’ judgmental accuracy and confidence. A 'hard-easy' effect was observed: nurses were overconfident in difficult judgments and underconfident in easy judgments. Conclusion: Nurses were poorly calibrated when making risk assessment judgments in a high fidelity simulated setting. Nurses with more experience tended toward overconfidence. Whilst time pressure had little effect on calibration, nurses’ over/underconfidence varied significantly with the degree of task difficulty. More research is required to identify strategies to minimize such cognitive biases

Effects of instruction presentation mode in comparative judgments

In each of two experiments, the comparative instructions in a symbolic comparison task were either varied randomly from trial to trial (mixed blocks) or left constant (pure blocks) within blocks of trials. In the first experiment, every stimulus was compared with every other stimulus. The symbolic distance effect (DE) was enhanced, and the semantic congruity effect (SCE) was significantly larger, when the instructions were randomized than when they were blocked. In a second experiment, each stimulus was paired with only one other stimulus. The SCE was again larger when instructions were randomized than when they were blocked. The enhanced SCE and DE with randomized instructions follow naturally from evidence accrual views of comparative judgments